MODIS/Aqua Land Surface Temperature/3-Band Emissivity Daily L3 Global 1km SIN Grid Day V061

Description

A suite of MODIS Land Surface Temperature and Emissivity (LST&E) products are available in Collection 6.1. The MYD21 LST algorithm differs from the algorithm of the MYD11 (https://doi.org/10.5067/modis/myd11_l2.061) LST products, in that the MYD21 algorithm is based on the ASTER Temperature/Emissivity Separation (TES) technique, whereas the MYD11 uses the split-window technique. The MYD21 TES algorithm uses a physics-based algorithm to retrieve dynamically both the LST and spectral emissivity simultaneously from the three MODIS thermal infrared bands 29, 31, and 32. The TES algorithm is combined with an improved Water Vapor Scaling (WVS) atmospheric correction scheme to stabilize the retrieval during very warm and humid conditions. The MYD21A1D dataset is produced daily from daytime Level 2 Gridded (L2G) intermediate LST products. The L2G process maps the daily MYD21 (https://doi.org/10.5067/MODIS/MYD21.061) swath granules onto a sinusoidal MODIS grid and stores all observations falling over a gridded cell for a given day. The MOD21A1 algorithm sorts through all these observations for each cell and estimates the final LST value as an average from all observations that are cloud free and have good LST&E accuracies. The daytime average is weighted by the observation coverage for that cell. Only observations having observation coverage more than a certain threshold (15%) are considered for this averaging. The MYD21A1D product contains seven Science Datasets (SDS), which include the calculated LST as well as quality control, the three emissivity bands, view zenith angle, and time of observation. Additional details regarding the methodology used to create this Level 3 (L3) product are available in the Algorithm Theoretical Basis Document (ATBD (https://lpdaac.usgs.gov/documents/1399/MOD21_ATBD.pdf)). Validation at stage 1 (https://modis-land.gsfc.nasa.gov/MODLAND_val.html) has been achieved for the MODIS Land Surface Temperature and Emissivity data products. Further details regarding MODIS land product validation for the MYD21 data products are available from the MODIS Land Team Validation site (https://modis-land.gsfc.nasa.gov/ValStatus.php?ProductID=MOD21). Improvements/Changes from Previous Versions * The Version 6.1 Level-1B (L1B) products have been improved by undergoing various calibration changes that include: changes to the response-versus-scan angle (RVS) approach that affects reflectance bands for Aqua and Terra MODIS, corrections to adjust for the optical crosstalk in Terra MODIS infrared (IR) bands, and corrections to the Terra MODIS forward look-up table (LUT) update for the period 2012 - 2017. * A polarization correction has been applied to the L1B Reflective Solar Bands (RSB). * The product utilizes GEOS data replacing MERRA2. * Three new CMG products are available in the MxD21 suite (MxD21C1/C2/C3).

Resources

Name Format Description Link
20 Earthdata Search allows users to search, discover, visualize, refine, and access NASA Earth Observation data. https://search.earthdata.nasa.gov/search?q=C2565805783-LPCLOUD
21 The LP DAAC website provides detailed information on discovery, distribution, access, and support of land data products. https://lpdaac.usgs.gov/
21 Browse image for Earthdata Search https://cmr.earthdata.nasa.gov/browse-scaler/browse_images/granules/G2689275133-LPCLOUD?h=85&w=85
21 Search results for publications that cite this dataset by its DOI. https://scholar.google.com/scholar?q=10.5067%2FMODIS%2FMYD21A1D.061
21 The LP DAAC product page provides information on Science Data Set layers and links for user guides, ATBDs, data access, tools, customer support, etc. https://doi.org/10.5067/MODIS/MYD21A1D.061
33 The ATBD provides physical theory and mathematical procedures for the calculations used to produce the data products. https://lpdaac.usgs.gov/documents/1399/MOD21_ATBD.pdf
21 Further details regarding MODIS land product validation for the MYD21 data products are available from the MODIS Land Team Validation site. https://modis-land.gsfc.nasa.gov/ValStatus.php?ProductID=MOD21
20 LP DAAC Data Pool provides direct access to available products via HTTPS. https://e4ftl01.cr.usgs.gov/MOLA/MYD21A1D.061/
21 The Application for Extracting and Exploring Analysis Ready Samples (AρρEEARS) offers a simple and efficient way to perform data access and transformation processes. https://appeears.earthdatacloud.nasa.gov/
21 OPeNDAP provides direct access to data via HTTPS. https://opendap.cr.usgs.gov/opendap/hyrax/DP130/MOLA/MYD21A1D.061/contents.html
21 Validation at stage 1 has been achieved for the MODIS Land Surface Temperature and Emissivity data products. https://modis-land.gsfc.nasa.gov/MODLAND_val.html
21 The File Specification provides a description of the product file including Scientific Data Sets and their attributes. https://ladsweb.modaps.eosdis.nasa.gov/filespec/MODIS/6/MYD21A1D
33 The technical information in the User's Guide enables users to interpret and use the data products. https://lpdaac.usgs.gov/documents/1398/MOD21_User_Guide_V61.pdf

Tags

  • land-surface
  • national-geospatial-data-asset
  • ngda
  • surface-radiative-properties
  • surface-thermal-properties
  • earth-science

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